Dawg, with holes drilled in those, they would be IDEAL for vegging a lot of plants in a fairly smal 'footprint' for a short time, BUT there's a couple other things to think about.

-Crowding: The roots may be happy, but too many plants too close together will crowd each other as they compete for light, and you will see more VERTICAL growth than you want, generally not desirable indoors. Also the low leaves and branches will not get good circulation = harbor moisture, pests, mold, yuck.

-Space to grow: A gallon per foot of main stem is standard. A single-cola plant that finishes at 3 feet tall needs to at some point be transplanted into a 3 gallon pot. A trained plant with multiple tops needs more space.